Recuperative furnace



W. S. ROCKWELL.

RECUPERATIVE FURN-ACE.

APPLICATIQN mm Nov. 4, 1919.

Pmfsm Nov., 9, @2%

2 SHEETS-SHEET l.

W. S. ROCKWELL.

RECUPERTIVEFUBNCE.

APPLicMloN 511.51) Nov. 4, |919.

Pmmme Nova @9 M20@ 2 SHEETSvSHEET 2i sosrre PATENroFFIcE.

WALTER s. nocnwnnr., or new Yoan, n. v., nssrsnon Tof s. nocnwnnn corr- PANY, OF NEW`YORK, N. Y.,-A C'ORPCJRATIOUIv OIE JERSEY.

nncurnnlnrrvn runuacn.

assassin..

To all whom t may concern.;

Be it known that WAL'rnR S. RoenwnLL, a citizen of the vnited States, residing at v() West 106th. street, New Yer-lr,

countyrof- New York, and "State ofl New York, have invented certain-new and useful linproverrientsV in ltecuperative Furnaces,

fully described and represented in the following specification and the accompanying drawings, forming apart of the saine.

The present invention consists of a furnace having means to deliver a supply of air to burners fed with gaseous fuel, means to accelerate the .mixture of the air and gas before and during combustion, means to heat the air by the waste gases when desired, and means to heat both the upper and the mixing-chamber of the burner .mired l with the products' delivered fromthe burner.

The ,lower side of the hearth is heatedwhen required, by extending a sub-chamber beneath substantially the whole area of the hearth, and passing the waste gases through such sub-chamber when they first escape b from the" heating-chamber,

'lhe improvements in the furnace are adapted for use with burners applied directly to the heating-chamber of a furnace, or to any chamber therein.

The term furnace-chamber is used herein to express any chamber to whichvthe 'burner delivers the fuel for combustion.

lThe invention will be understood by reference to the annexed drawing, in which Figure l'is a crosssection of the furnace taken on line 1 1 in lfig. 2; and llig. 2 is a vertical section on line 2-2 in Fig. l. The lower half of Fig. 3 is a sectional plan'at the level of 'the burner centers, with the hearth broken away at the right-hand end to the center line of the discharge vent. ln

Specification of Letters Fatent.

Patented Nov. 9, 1920.

application slee november a, 1ere. seria; no. 335,601.'

the upper right-hand corner, Fig. 3 is a horizontal section on line -m in Fig. 2; and in the upper left-hand corner is a horizontal section on line z-z in Fig. l.

- ln the drawing, A designates 'the heatingchamber with hearth A and doorway al?. B designates a sub-chamber extended below substantially the whole area of the hearth A to heat the same, and C, C are outletchambers for heating the air used in combastion. The waste gases pass from the heatingchamber into the sub chamber through descending passages d and from the sub-chamber into the outlet-chambers by penings D, which form part of the outer ue.

The extension of the sub-'chamber below` substantially the whole area of the hearth causes a great expansion of the heated gases which enter such chamber. Such expansion greatly rgtards'the flow of the gases and thus retains them much longerin contact with the lower side ofthe hearth than is possible .with any smaller area below the hearth.

the heat in the gases, and heats the lower side of the hearth to substantially the same temperature as the upper side without any and @"-to at least one of the mixing chambers, tolsupply the air required for combustion. f 'il so-called induction-passage 'e2 extends from the mining-chamber through the inner side of the wall in line with the blastinlet, .which thus propels the gaseous fuel through the mixing-chamber and the induction-passage into the heating-chamber A. j The induction-passage, as shown at e2 in l? ig. 2, is of circular cross-section, andthe gaseous fuel being provided under pressure expands as it enters the mixing-chamber, and owing to the circular form of the induction-passage lthe blast entirely fills it in its movement to the heating-chamber, as indicated by the dotsa` in F ig. l, which show `the movement of the fuel through the induction-passage.

l 80 i This secures 'a far greater utilization of This passage thus operates as an ejector' in connection with the mixing-chamber to draw into the' chamber and deliver to the heating-chamber a supply of air which is automatically regulated bythe velocity and volume of thegaseous fuel moving through the induction-passage.

`When properly proportioned, the induction-passage is filled by the blast or current of entering gases whether the volume of the blast is at the minimum or maximum required to maintain the desired condition in the furnace.

This filling of the induction-passage tends to resist the pressure of the gases in the heating-chamber, and to more or less vary the volume of-induced heated air in proportion to the volume or velocity of the current injected into the mixing-chamber by the blast.

The circular form of the induction-passage is important, as the uniform expansion of the gases causes them to completely fill such passage and produce an ejector effect,

which would not so effectively be produced if the passage were square or had angular corners. i

Means are pro-vided for -controlling the flow of gaseous fuel to the burner, but the heated air supply is automatically controlled in the manner just described, so that Acombustion is thus heated without any consumption of fuel. y

`The inlet of the air-duct is extendedto the atmosphere /at the damper f, and its 5' outlet is connected with,the""hotair-duct b which delivers the hot air into the mixingchamber, Where it lis rapidly mixed with the gaseousfuel and ignited before it enters the heating-chamber A..

rthe sub-chamber B is also, without any consumption of fuel, heated to a high temperature by the passage of the burning gases directly to Vthe sub-chamber through the descending passages d. rlhe high temperature of the sub-chamber B would unit it for use as a recuperative chamber, but'the chambers C' and C receive the waste gases after they have yielded up much of theirl heat, so as not to exert an injurious effectv upon the air-duct e.

r1`he vcombination of the burner-inlet ranas-iso (which is formed `with a blast-passage e,

mixing-chamber e, and the induction-pasfsage e2) with the means for heating the air and leadi'ig it directly into the mixingehamber without any expenditure of fuel, secures a high degree of efficiency in the generation of heat in the heating-chamber, and the utilization of such heat for heating the under side of the hearth and the air employed in combustion.

Separate outlet-chambers are shown to supply with hot air the burners at each side ,of the heating-chamber, but more or fewer of such outlet-chambers. may be provided as preferred. l

The air passing vthrough the duct c moves in an opposite direction to the spent gases traveling through the outlet-chamber to its outlet.

This is an advantageous construction, a it exposes the air constantly to an increasing temperature in the outlet-chambers, and thus secures a greater absorption 0f heat by the air. rllhis feature is not however essential to the operation of the'invention.

'lhe most important feature of the invention frdm a commercial point of view,

y is the connection7 with the heating-chamber,

of the outlet-fine and air-duct t0 heat the air for combustion, and the provision of the burner-inlet with a blast-inlet, an eX.- panded mixing-chamber'connected to the air-duct; and a round induction-passage which operates to induce and control the supply of air tothe burner.

f am aware that it is common to use the waste gases of a furnace to heat air to promote the combustion of the fuel, but l am not aware that the air lthus heated has been supplied-teeny gases in combustion by such meansas 1 have claimed.

1t is also old to conduct the waste gases below the hearth of the heating-chamber,

but 1 am not aware that a sub-chamber has ever been extended beneath the entire lower side of the hearth' and the waste. gases conducted through the same. This is a very advantageous arrangement, as it heats the lower side of the hearth almost as hot as the upper side, without any additional expense. Having thus set forth the nature of the invention what is claimed herein is:

l. A furnace having a heating-chamber,

a burner applied to the wall of the furnace and having a blast-inlet inserted in said wall with a mixing-chamber intersecting the blast-inlet within the wall, and an. induction-passage extending from the mixingchamber into the heating-chamber in line .vith the blast-inlet, an outlet-flue discharging the waste 'gases from the heating-chamber, and an aireduct connected with the atmosphere and eirtended contiguous to the outlet-Hue and connected with the mixingchamber'independently of the burner, to

iso

supply the mixingcliai1iber With heated air,

the whole larranged and operated substarr 'withthe heatingcl'iainber to discharge'the Waste gases, and an air-duct connected With ,the atmosphere and extended contiguous to the outlet-flue into connection with the mixn'ig-chaznber, as and lfor the purpose set forth.

3. mixing-chamber constructed accordf ing to claim 2 with the induction-passagel formed or" circular cross section toproduce with the blast an ejector effect upon-the air in: the airduct..

l. A furnace having a heating-chamber, a burner applied to the Wall of the heatingehamber and having a blast-inlet in said wall, with an expanded mixing-chamber inlerseeting the blastsinlet Within the said wall and an induction-passage oflcircular cross section extended from the mixing-chamber into the heating-chamber, an outletlue discharging the Waste gases trom the heatingchaniber, a recuperative chamber intersectin'g the outlet-Hue, with the spent gases passing through the same, and an air-duct con- .nected with the atmosphere and extended through the recuperative-charnber into conL n'cctioh 'with the Y mixing-chamber of the burner to supplyv heated air thereto indeheat`ingchamber, a

pendently ot' the mast, the whole arranged and oerated substantially as set orth.

`furnace having a heating-chamber 'with a sub-chamberi beneath the entire lower 'c side of its hearth and gas-passages leading f thenaste gases thereinto, anvoutlet-lue eX- tended ,from the` sub-chamber, a recupera tiv`e-cha1nber intersecting the said outlet-flue and having an air-duct therein'heated by. the spent gases, and afuel-burnei* applied to the wall of the furnace-chamber and sup plied -withheated air from the said air-duct,

whereby the. Waste gases operate consecue tively to heat the .under side of the hearth and to heat the air` for the combustion of the fuel.

heating-furnace having a heating chamberwith a-sub-charnber beneath the entire lower side of its hearth and gas-passages leading the waste lgases thereinto, an outlet-Hue extended trom the sub-chamber, a

recuperativechamber intersecting the Said outlettiue and havlng an air-duct heated bythe spent gases, a blast-inlet in the Wall i the .metal-heating chamber, a inixingchamber intersecting the blast-inlet Within thesaid Wall, an induction-passage eiitend ed,l from the mixing-chamber into the heat'- ing-chamber, and a connection from the said air-duct to the mixing-chamber to supply it with heated air, whereby the Waste gases operate consecutively to heat the under side of the hearth and to heat the air forthe combustion of the fuel. Y. y

In testimony Whereoiz l have hereunto set 1n handL Y .y WALTER S. llt@ClUFVElLlL.y 

